PITTSBURGH  It sounds like a free-market success story: a natural-gas boom created by drilling company innovation, delivering a vast new source of cheap energy without the government subsidies that solar and wind power demand.

The free market has worked its magic, the Barnett Shale Energy Education Council, an industry group, claimed over the summer.

The boom happened away from the greedy grasp of Washington, the American Enterprise Institute, a think tank, wrote in an essay this year.

If bureaucrats had known this was going on, the essay went on, surely Washington would have done something to slow it down, tax it more, or stop it altogether.

But those who helped pioneer the technique known as hydraulic fracturing, or fracking, recall a different path. Over three decades, from the shale fields of Texas and Wyoming to the Marcellus in the Northeast, the federal government contributed more than $100 million in research to develop fracking, and billions more in tax breaks.

Now, those industry pioneers say their own effort shows that the government should back research into future sources of energy  for decades, if need be  to promote breakthroughs. For all its success now, many people in the natural-gas and oil industry itself once thought shale gas was a waste of time.

Theres no point in mincing words. Some people thought it was stupid, said Dan Steward, a geologist who began working with the Texas natural-gas firm Mitchell Energy in 1981. Steward estimated that in the early years, probably 90 percent of the people in the firm didnt believe shale gas would be profitable.

Did I know it was going to work? Hell no, Steward said.

Shale is a rock formation thousands of feet underground. Among its largest U.S. deposits are the Marcellus Shale, under parts of Pennsylvania, New York, Ohio and West Virginia, and the Barnett Shale is in north Texas. Geologists knew shale contained gas, but for more than 100 years the industry focused on shallower reserves. With fracking, large volumes of water, along with sand and chemicals, are injected underground to break rock apart and free the gas.

In 1975, the Department of Energy began funding research into fracking and horizontal drilling, where wells go down and then sideways for thousands of feet. But it took more than 20 years to perfect the process.

Alex Crawley, a former Department of Energy employee, recalled that some early tests were spectacular  in a bad way.

A test of fracking explosives in Morgantown, W.Va., blew the pipe out of the well about 600 feet high in the 1970s, Crawley said. Luckily, no one was killed. He added that a 1975 test well in Wyoming produced a lot of water.

Steward recalled that Mitchell Energy didnt even cover the cost of fracking on shale tests until the 36th well was drilled.

Theres not a lot of companies that would stay with something this long. Most companies would have given up, he said, crediting founder George Mitchell as a visionary who also got support from the government at key points.

The government has to be involved, to some degree, with new technologies, Steward said.

The first federal energy subsidies began in 1916, and until the 1970s they focused almost exclusively on increasing the production of domestic oil and natural gas, according to the Congressional Budget Office.

More recently, the natural-gas and petroleum industries altogether accounted for about $2.8 billion in federal energy subsidies in the 2010 fiscal year and about $14.7 billion went to renewable energies, the Department of Energy found. The figures include both direct expenditures and tax credits.